Compressor piston cooling system



A. J. WAIBEL COMPRESSOR PISTON COOLING SYSTEM Filed Nov. 25, 1958 Aug.7, 1962 INVENTOR ANTHONY J. WA/BEL HIS ATTORNEY g a. w I .17//////flUnited States Patent 3,048,411 COMPRESSOR PISTON COOLING SYSTEM AnthonyJ. Waibel, Painted Post, N.Y., assignor to Ingersoll-Rand Company, NewYork, N.Y., a corporation of New Jersey Filed Nov. 25, 1958, Ser. No.776,311 1 Claim. (Cl. 277--74) The invention relates to compressors, andmore particularly to a cooling system for the piston of high pressurereciprocating gas compressor.

This application is a continuation-in-part of my copending applicationSerial No. 579,328, filed April 19, 1956, now abandoned.

One object of this invention is to provide such a cooling system whichis readily adaptable to existing compressor designs.

Another object is to provide a cooling system which is relativelyinexpensive in construction.

Another object is to provide a cooling system in which the coolant isrecovered.

Further objects will become obvious from the following specification anddrawings in which,

FIGURE 1 is a longitudinal section showing one form of the inventionadapted to a high pressure compressor,

FIG. 2 is a view of the cooling fluid distributing ring for the shaft,and

FIG. 3 is an enlarged longitudinal section showing another form of theinvention shown in FIGURE 1.

Referring to the drawings, the invention is shown adapted to aconventional high pressure reciprocating gas compressor. The compressorshown by way of illustration comprises, in general, a casing having acentral bore 12 housing a plurality of pressure seals I4- mounted on areciprocating plunger type piston 16. The free end of the pistonreciprocates in a compression chamber 18 formed in a cylinder 20 mountedin one end portion of the bore 12. A cap member 22 is mounted in theopposite end of the bore 12 and bolted to the casing 10. The cap servesto clamp the seals 14 against the cylinder 20 and to support the piston16.

In this type of compressor-that is compressors used for compressing gasup to several thousand pounds per square inch-the seals are commonlyheld in sealing relation with the piston by means of the pressure of thefluid being pumped. As a consequence of this relatively high forceexerted on the seal, considerable friction is generated between the sealand piston '16.

A common means for cooling the piston is to drill a central passage inthe piston and supply oil to the passage to conduct the heat from thepiston. The difliculty with this construction is that it is quiteexpensive and to some extent weakens the piston structure. The presentinvention avoids these difliculties with a cooling system whereby acooling fluid, such as air, oil or an inert gas, is conducted around theperiphery of the piston.

In furtherance to this end a cooling fluid distributing ring ispositioned to direct cooling fluid on the piston at or near the outerend piston seal. More particularly a bearing element 24 mounted in thecap 22 and encircling the piston 16 is formed with inner and outerperipheral grooves 26 and '28, respectively, communicated through holes30. Cooling fluid is supplied to the outer grooves 28 through a passage32 formed in the cap 22.

With this cooling system cooling fluid is conducted from a supply (notshown) through the passage 32 around the groove 28 and thence throughthe holes 30 and directed at the periphery of the piston 16. The pistonin reciprocating through the bearing is cooled along its length adistance equal to the piston stroke plus the width of the groove 26.Experience has shown that this method of cooling is extremely effectivefor the length 3,ii43, l-ll Patented Aug. 7, Iss2 ICC of the pistonexposed directly to such fluid. Moreover it maintains this portion ofthe piston sufliciently cool such that the free end portion of thepiston not exposed directly to such cooling fluid is also maintained ata satisfactory low temperature in that the heat from the latter portionof the piston is conducted along the piston to the directly cooledportion.

The cooling fluid after contact with the piston flows therealong to theexterior, or outer end, of the cap 22. When it is desired to save thecooling fluid for recirculation fluid, as for example when such fluid isoil, a drain chamber may be provided in the casing part 34 in which adrain port 36 is provided.

FIG. 3 illustrates another form of the invention shown in FIGS. 1 and 2disclosing a structure which serves as another way of eflectivelycooling the piston, and of saving the cooling fluid for recirculation.All parts corre sponding to those in FIGS. 1 and 2 have the samenumerals with the addition of a prime In the present form of theinvention the cooling fluid is not allowed to flow to the outer end ofthe cap 22 and into the drain shown in FIG. 1, but is directed from oneend of the groove 26 to the opposite end thereof to exhaust passagewayswhich communicate with the groove 26' and the supply (not shown).Accordingly, an exhaust passage 38 extends through the lower half of thecap 22' and communicates with the outer end portion 39 of the innerperipheral groove 26' through exhaust passage 40 of the bearing element24. The passage 38 extends from the passage 40 to a supply (not shown)and conveys exhaust fluid thereto.

The exhaust passage 40 comprises an outer peripheral groove 42. and aport 44 communicating the outer end portion 39 of the inner peripheralgroove 26' with the groove 42. The outer peripheral groove 23' and holes30' are longitudinally displaced from the exhaust passage 40 with theholes 30 communicating with the inner end portion 41 of the groove 26.

In order to limit leakage along the rod 16 seals 46 are provided onopposite ends of the bearing element 24. The seals 46 encircle the rod16 and are housed in undercuts 48 in opposite ends of said element 24'.The seals 46 are held against longitudinal movement by clamping means,or cover, 50 which is secured to the cap 22 at the outer end thereof bybolts 52. The clamping means 50 abuts one end of the outer seal 46 andelement 24 and holds said element 24- against seal 14'.

In addition to the seals 46, O-rings 54 serve to limit leakage ofcoolant between complementary fitted parts.

With this cooling system cooling fluid is conducted from a supply (notshown) through passage 32' around the groove 28 and thence through holes30' and directed at the periphery of the rod 16 located. at the innerend portion 41 of the groove 26. Therefore, the coolant first comes incontact with the piston portion nearest its free end and flows awaytherefrom to the outer end portion 39 of the groove 26 into the passage4-0 and back to the supply (not shown) via exhaust passage 38. It is to-be noted that the coolant flows from one end of the groove 26' to theopposite end thereof, thereby obtaining maximum effect from the coolant.

While I have shown and described two forms of my invention, it is to beunderstood that various changes and modifications may be made withoutdeparting from the spirit of the invention as set forth in the appendedclaim.

I claim:

A cooling ring for admitting coolant fluid to a piston reciprocatingwithin a casing and having a rod for reciprocating the piston and saidcasing having an inlet for coolant fluid, said cooling ring comprising,a central bore through the ring for receiving said piston rod, an outerannular groove about the outer periphery of said ring hausted, a secondouter peripheral groove communicating 10 with said exhaust port forexhausting said inner annular groove, and undercuts located in theopposite ends of 4 said ring for housing seals thereby limiting leakagealong said rod.

References Cited in the file of this patent UNITED STATES PATENTS774,270 Palmer Nov. 8, 1904 1,776,974 Henderson Sept. 30, 1930 1,990,519Bigelow et al Feb. 12, 1935 2,143,637 Vollman Ian. 10, 1939 2,259,361Vorkauf Oct. 14, 1941 2,390,602 Maier Dec. 11, 1945 maul.-

